From: Ken Bloom <kbloom@...>
Date: 2006-10-19T10:00:07+09:00
Subject: Re: whats this lambda code doing?

On Thu, 19 Oct 2006 09:48:07 +0900, hemant wrote:

> I came across following code in typo's application.rb and I can't
> understand the last part,
> 
> 
>   def with_blog_scoped_classes(klasses=[Content, Article, Comment,
> Page, Trackback], &block)
>     default_id = this_blog.id
>     scope_hash = { :find => { :conditions => "blog_id = #{default_id}"},
>                    :create => { :blog_id => default_id } }
>     klasses.inject(block) do |blk, klass|
>       lambda { klass.with_scope(scope_hash, &blk) }
>     end.call
>   end
> 
> Method will be called with a block and will probably add some scope to
> the respective methods of ActiveRecord classes. But whats the last
> part?
> I mean, end.call?

The whole do...end thing (and its binding to the inject call) has higher
precedence than the method call that follows it. It's equivalent to

x=klasses.inject(block) do
	...
end
x.call

-- 
Ken Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu/~kbloom1/
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